Numerous devices and methods for detecting one or multiple properties of gases in a measuring gas chamber are known from the related art. For example, the gas may be an exhaust gas of an internal combustion engine, in particular in the automotive sector, and the measuring gas chamber may be an exhaust tract, for example. Alternatively or additionally, however, other properties of the gas may be detected, such as any given physical and/or chemical parameters of the gas, or a different type of gas may be involved.
Many of the methods and devices are based on the use of electrochemical sensor elements. In particular, these may be electrochemical sensor elements which are based on the use of one or multiple solid electrolytes, i.e., the use of solid bodies which have ion-conducting properties, for example oxygen ion-conducting properties, at least above a minimum temperature. For example, this may involve zirconium dioxide-based solid electrolytes such as yttrium-stabilized zirconium dioxide (YSZ) and/or scandium-doped zirconium dioxide (ScSZ). These types of sensors may be used, for example, for determining an air ratio of an exhaust gas. Examples of these types of sensors, also referred to as lambda sensors, are discussed in Robert Bosch GmbH: Sensoren im Kraftfahrzeug (Automotive Sensors), 2007 Edition, pages 154-159. The sensors discussed therein may, in principle, also be used within the scope of the present invention and modified according to the present invention. In addition, sensors for determining a nitrogen oxide (NOx) component, for example, may be used. These types of sensors are discussed in EP 0 769 693 A1, DE 10 2008 040 314 A1, or WO 2010/003826 A1, for example. The devices and methods described in these publications may, in principle, also be employed within the scope of the present invention and modified and used according to the present invention.
In practice, for such methods and devices it has been shown that the measured values ascertained with the aid of these methods and devices, for example measured values of a selective detection of one or multiple gas components, may be greatly dependent on the environmental conditions. In particular, the measured values may be a function of disturbance variables and cross sensitivities, which may have an interfering effect in particular for a quantitative, selective detection of one or multiple gas components, for example O2 and/or NOx, with high resolution, in particular for use as on-board diagnostic sensors. To achieve a required detection accuracy (for example, a NOx detection in the single-digit ppm range), it is therefore necessary in many cases, in addition to the pure sensitivity of the sensor, to likewise minimize one, multiple, or all occurring disturbance variables and cross sensitivities. In particular, a temperature dependency of the sensor signals must be taken into consideration here. Therefore, in the related art the temperature within the sensor element is generally determined, and the temperature is generally regulated to a setpoint temperature. However, there is still tremendous potential for improvement regarding the minimization or consideration of interfering effects, in particular also the temperature effects on the overall sensor element.